Tactics and post-mortem analysis wins by far, in my opinion. Especially for the beginner level you've described. Of course everyone of them is important but for a beginner, studying top level games and openings shouldn't be prioritized.
What is the fastest way to improve

dont assume that none of the tactics puzzles you do will never come up in a real game. most of these actually are taken from real games!

It depends on what level you're shooting for... I say that because the fastest immediate improvement (method 1) is slower overall because it sets you up for roadblocks later.
You ask at the end which is best, and yes, you need a mixture of skills. You should learn the basic strategic ideas like the different types of pawn (chains, islands, doubled, backward, isolated etc) and how knights like "outposts" how rooks like open files... things like that. After you get better strategically, you can drop that area and go back to tactics or endgames.
Two areas that aren't very useful for the novice you describe are opening study and traps and watching top level games. You shouldn't completely ignore openings, but you need very little other than the basic opening principls (e.g. development, the center, castling etc.) As for top level games, that kind of study can be useful, but instead of watching it's better if they're out of a book and have explanations (annotated games) such as Chernev's book "Logical Chess Move by Move."
Agreeing with philidor_position how analysing your games afterwards for mistakes is one of the best things you can do for yourself. Best to use a chess engine if you don't have strong player to help you with this (there are plenty of free engines online).

A great article about analyzing your own games:
http://kebuchess.com/blog/post/How-to-analyze-your-own-games.aspx

A great article about analyzing your own games:
http://kebuchess.com/blog/post/How-to-analyze-your-own-games.aspx
Thanks for the link! It's very helpful :)

You cant just do one and then become master. You need to study them all.
Get a OTB coach that can help you.

You cant just do one and then become master. You need to study them all.
Get a OTB coach that can help you.
I live out of town (in the country). The nearest official chess club takes about 3 hours to get to, though there is a really casual unofficial club about 30 minutes away. Also, I can't afford a coach even if I lived in the city.

You cannot do 4. or 5. without 2. And if you want to encourage the conditions for 1. (rather than just hoping they materialize) you need 2. also.
With regard your 3.: "mesmerizing" openings ain't gonna help. Even memorizing is going to be useless if your opponent takes you into non-memorized lines (unless you can memorize all openings?).
Here are some positional books that might help you:
Stean - Simple Chess (2002)
Seirawan - Winning Chess Strategies (2003)
Silman - How To Reassess Your Chess (1993)
Horowitz & Mott-Smith - Point Count Chess (1960)
Pachman - Modern Chess Strategy (1963)
Nimzovich - My System (1925)
Nimzovich - Chess Praxis (1929)
Euwe & Kramer - The Middlegame Series (1964)
What is the fastest way to improve chess skills?
Let's say you're not a complete novice. You know where all the pieces move, you know a few basic openings, you understand how to win basic endgames such as king and rook vs king and you also know about pins, forks and skewers, and sacrifices to bring them to you.
So basically, once you are at a stage where you know most (if not all) of the tricks, but it is just a matter of being able to "see" them in a chess game. What is the best way to improve from then on?
I've heard many different responses from a variety of people and I'm not sure which works the best. These answers include:
1. Chess tactics. Just smother yourself in middlegame chess tactics and try to find forced moves or the best move you can get for any given position. Although the specific tactics may not be repeated in a real game, you may improve mentally at "seeing" such things in a real game.
2. Positional understanding. Not always there is going to be a forced tactic to find, so when you are in a position where you are fully developed but you have no real tactics or immediate attacks/threats, it is important to learn to set up for things like this which may happen later in the future.
3. Chess openings/traps. If you know very good openings and sometimes traps in the openings, from just simple mesmerisation, you can try to race to develop or set up a trap in the opening which may win the game in a short amount of time, without the need for extensive middlegame or endgame practice.
4. Viewing top games. By watching a demonstration of more experienced players battle it off amongst each other, you can learn visually how they block and counter threats, as well as create their own ones. By seeing how it is done, you can then apply their skills and tricks into your own play.
5. Past game analysis. This is sort of similar to viewing top games, however this also includes analysing your own games. Whenever you lose a game, or play the same opponent in a series of games and lose a fair few of them, you can go over the games and see what important moves you may have overlooked. You can also notice a pattern or trend between the style that your opponent plays in a series of games and try to find his/her weakness. Also, don't feel limited to lost games only, you can analyse your wins to see what your opponent could have done instead or to see if you missed anything which would've made winning even easier for you.
Which do you think is best? Do you need a mixture of skills? Is there something which I forgot to put on the list? Thanks.